<!-- 模板是这样的 -->
var trHtml = '<tr id="dynamic-line-'+idRecord+'">'
    + '<td><input id="check-item-'+idRecord+'" type="checkbox" name="checkItem"></td>'
    + '<td>'+trCount+'</td>'
    + '<td><input id="student-id-'+idRecord+'" type="text"></td>'
    + '<td><input id="student-name-'+idRecord+'" type="text"></td>'
    + '<td>'
    +	'<select id="student-sex-'+idRecord+'">'
    +		'<option value="1">男</option>'
    +		'<option value="2">女</option>'
    +	'</select>'
    + '</td>'
    + '<td></td>';

    <!-- 添加用户的表项 -->
    var trHtml = '<tr id="adduser-line-'+idRecord+'">'
        + '<td>这里是姓名</td>'
        + '<td>这里是学号</td>'
        + '<td><button type="button" class="btn btn-sm btn-primary">同意</button><button type="button" class="btn btn-sm btn-primary">拒绝</button></td>';
    
        <!-- 原来的 -->
        <tr>
            <th scope="row">1</th>
            <td>Mark</td>
            <td>Otto</td>
            <td><button type="button" class="btn btn-sm btn-primary">同意</button><button type="button" class="btn btn-sm btn-primary">拒绝</button></td>
          </tr>
    
    <!-- 删除用户的表项 -->
    var trHtml = '<tr id="adduser-line-'+idRecord+'">'
        + '<td>这里是姓名</td>'
        + '<td>这里是学号</td>'
        + '<td><button type="button" class="btn btn-sm btn-primary">删除</button></td></td>';

        <!-- 原来的 -->
          <tr>
            <th scope="row">1</th>
            <td>Mark</td>
            <td>Otto</td>
            <td><button type="button" class="btn btn-sm btn-primary">删除</button></td>
          </tr>
    
    <!-- 批改列表的表项 -->
    var trHtml = '<tr id="adduser-line-'+idRecord+'">'
        + '<td>这里是姓名</td>'
        + '<td>这里是学号</td>'
        + '<td>这里是学号</td>'
        + '<td><a href="homework_check.html"><button type="submit" class="btn btn-primary">批改</button></a></td>';

        <!-- 原来的 -->
        <tr class="success">
            <th scope="row">1</th>
            <td>Column content</td>
            <td>Column content</td>
            <td>已批改</td>
            <td><a href="homework_check.html"><button type="submit" class="btn btn-primary">批改</button></a></td>
        </tr>